Aspirin Resistance a False Diagnosis for Heart Care

By Alex Nussbaum -
Dec 5, 2012

There’s no such thing as aspirin
resistance, according to a study that suggests a false diagnosis
may be unnecessarily raising the number of people given costlier
prescription drugs with more side effects to lower their risk of
heart attack and stroke.

The report, by University of Pennsylvania researchers,
found the coatings put on aspirin by makers such as Bayer AG (BAYN)
mask uptake of the medicine in the blood, leading to false
diagnoses that it’s not working, said the study published in the
journal Circulation. Patients are then put on a prescription
blood thinner, such as Bristol-Myers Squibb Co. (BMY)’s Plavix.

One in five Americans take a low-dose aspirin tablet daily
to reduce heart risks, with most taking coated versions sold as
less harsh on the stomach, the university said in a statement.
Garret FitzGerald, a lead researcher on the study, said there’s
no evidence showing the coatings make aspirin more tolerable.

“The takeaway for consumers is, don’t worry about
resistance,” FitzGerald said in a phone interview. “And if
you’re taking aspirin, there’s plenty of reason to take the
cheap, immediate-release uncoated version.”

Doctors had estimated aspirin may not work for about a
third of patients, FitzGerald said.

Not Unexpected

Bayer, which contributed funding for the research, said a
delayed uptake of coated aspirin “would not be unexpected,” in
an e-mail yesterday. The Leverkusen, Germany-based drugmaker’s
statement said the study was flawed because it tested aspirin on
a relatively young, healthy population instead of the sick
patients who would typically take it to prevent heart problems.

FitzGerald said he didn’t question the effectiveness of
coated tablets, but saw no evidence they provided any more value
for their price. There’s no reason to suggest sick patients
would have a genetic resistance to aspirin while healthy
patients wouldn’t, he said.

While the research suggests Bayer’s higher-cost coatings
may do more harm than good, it also contained some positives for
the company since it found more people may benefit from use of
aspirin as a blood thinner than previously thought, said
FitzGerald, director of the Institute for Translational Medicine
and Therapeutics at the Philadelphia school.

The research also calls into question the value of blood
and urine tests sold to diagnose supposed resistance, FitzGerald
said. Coated versions of aspirin, meanwhile, may cost 6 cents a
tablet compared to less than one cent for bare pills, he said.

“That’s unlikely to be a deal-breaker for most people, but
if you look at it from the level of national health spending,
and in an era of cost constraints, it starts to add up,”
FitzGerald said.

The study gave 400 patients coated and uncoated versions of
the medicine and found no consistent pattern of resistance,
researchers said in the journal, which is published by the
Dallas-based American Heart Association.

Plavix can have side effects including making patients
bleed and bruise more easily, New York-based Bristol-Myers says
on its website.